// https://leetcode.cn/problems/climbing-stairs/?envType=study-plan-v2&envId=top-interview-150

class Solution {
public:
    int climbStairs(int n) {
        vector<int> dp(n + 1);
        dp[0] = 1;
        dp[1] = 1;
        for (int i = 2; i <= n; i++) {
            dp[i] = dp[i - 1] + dp[i - 2];
        }
        return dp[n];
    }
};